JPH0824694B2 - Contact lenses for correcting blue eyes - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a contact lens for correcting blue eyes, and more particularly to a contact lens for correcting blue eyes occurring in aphakic eye patients after cataract surgery. .

[Prior Art] In recent years, the population of patients with senile cataract has been increasing with the increase of the elderly population. An aphakic eye patient whose lens has been removed by a cataract surgery generally performs visual acuity correction using any of eyeglasses, contact lenses, and intraocular lenses.

In the case of correction with eyeglasses, the correction lens becomes a thick convex lens and it looks bad, and since the retinal image becomes larger than the normal eye, especially in the case of a monocular aphakic eye, unequal vision occurs and eye strain increases. The burden on the user is heavy.

Therefore, in recent years, a contact lens that has excellent oxygen supply to the cornea and has a small burden on the cornea even when worn for a long time has been developed, and it is very effective in correcting visual acuity in aphakic patients. Further, an intraocular lens that does not need to be removed by being embedded in the eye has been developed and is becoming established in the market. These contact lenses and intraocular lenses have many advantages as the means for correcting visual acuity compared with the above-mentioned spectacles, and are expected to become more popular in the future.

By the way, it is known that ataxia develops in aphakic patients after cataract surgery. Blue eyesight is a symptom that occurs in the lens-extracted eye, in which a white object looks blue, and since the lens is originally a yellow or yellow and colored translucent body,
When the crystalline lens is removed, blue light (yellow or yellow and the remaining color of the color) reaches the retina without being attenuated, and as a result, the object appears blue compared to the normal eye (Ophthalmology, Rev. 14).
Edition, pages 28 and 277-288, Kanehara Publishing).

Therefore, there is a demand for a contact lens or an intraocular lens capable of correcting blue eyesight, and an example of using an ultraviolet absorber has been seen and has been partially commercialized for the purpose of bringing it closer to the light absorption characteristics peculiar to the crystalline lens. However, the ultraviolet absorber has very little absorption in the visible region and can absorb ultraviolet rays having a harmful wavelength of 400 nm or less, but cannot absorb visible blue light, so that correction of blue eyesight is incomplete. Further, if a large amount of an ultraviolet absorber is used to increase the absorption of light in the visible region, the physical properties of the lens material are often deteriorated, which is not preferable.

On the other hand, coloring of contact lenses has been conventionally performed and generalized, but the purpose of conventional coloring is only to make the lenses easily distinguishable when the lenses are used, and a coloring agent for correcting blue eyesight. Therefore, in reality, there is no contact lens that has been colored to positively intend absorption in a specific wavelength range.

[Problems to be Solved by the Invention] An object of the present invention is to provide a contact lens capable of correcting blue eyesight that occurs in an aphakic eye after cataract surgery.

[Means for Solving the Problems] The present invention has been made to achieve the above object, and the contact lens for correcting blue eyesight according to the present invention has a transparent lens material containing a yellow or orange colorant. And a transparent coloring material obtained by introducing an ultraviolet absorber.

 Hereinafter, the present invention will be described in detail.

The blue-vision correcting contact lens of the present invention comprises a transparent coloring material obtained by introducing a yellow or orange coloring agent and an ultraviolet absorber into the transparent lens material.

The transparent lens material constituting the base material of the contact lens for blue-vision correction of the present invention is not particularly limited as long as it has characteristics required as a transparent lens material,
Polymethylmethacrylate (PMMA), which is commonly used for contact lenses, is typical. In addition to these, (meth) acrylic polymers such as fluorine-containing or silicone-containing (meth) acrylates which have been used for oxygen permeable hard contact lenses in recent years, or cellulose derivatives, and transparent plastics such as polystyrene and polycarbonate can be mentioned. Furthermore, transparent rubber materials such as silicone rubber are also effective.

It is preferable that the yellow or orange coloring material and the ultraviolet absorber are introduced into the transparent lens material at the same time when the transparent material as the contact lens base material is manufactured. That is, by adding a colorant and an ultraviolet absorber to a monomer mixture for forming a contact lens base material (for example, methylmethacrylate as a main component and adding a polymerization initiator, etc.) and casting polymerization, the colorant and the ultraviolet absorber are absorbed. A colored contact lens in which the agent is dispersed is obtained.

Instead of the cast polymerization method, a method of obtaining a contact lens by obtaining a button-shaped or rod-shaped polymer and then cutting and polishing the polymer may be adopted. Alternatively, the contact polymer may be obtained by pelletizing the colored polymer obtained by polymerization and injection or compression molding.

The colorant is the most important substance together with the ultraviolet absorber in the contact lens for correcting blue eyes of the present invention, and the compound used as the colorant is yellow to orange,
Compounds with a maximum absorption wavelength between 320 nm and 450 nm are preferably suitable.

Examples of colorants include IC Solvent Yellow and CI listed in the Color Index (CI).
Oil-soluble dyes such as Solvent Orange or CI Disperse Yello
w), CI Disperse Orange
And the like are suitable. Any colorant other than those described above may be used as long as it has a good compatibility with the transparent lens material, and for example, a vat dye or the like may be used. Particularly preferred colorants are CI Solvent Yellow 44, CI Solvent Yellow 16, CI Solvent Yellow 77, CI Disperse Yellow 3 and other compounds having a maximum absorption wavelength in the vicinity of 350 to 440 nm. These colorants have absorption of visible light of 400 to 500 nm, and the UV absorption region of the crystalline lens is 300 to 400 nm.
It can absorb nm light at the same time. Therefore, it is possible to absorb ultraviolet light and visible blue light, and the object of the present invention can be achieved with the least amount of use.

It is also possible to use a colorant having the same chemical structure part as the above-mentioned colorant and having a part which can be copolymerized with the contact lens base material forming monomer.

In addition, in the contact lens for correcting blue eyes of the present invention, it is an essential condition to use a UV absorber together with the colorant as described above, whereby a light ray having a wavelength of 300 nm to 450 nm can be absorbed. Therefore, it is possible to further approximate the light absorption characteristics of the human crystalline lens by selecting the type and concentration of the coloring agent according to the visible absorption characteristic of the human crystalline lens and supplementing the insufficient absorption in the ultraviolet with an ultraviolet absorber. It is possible.

Examples of such an ultraviolet absorber include: benzotriazole-based 2- (2'-hydroxy-5'-methylphenyl) benzotriazole [Tinuvin P, manufactured by Ciba Geigy], 2- (2'-hydroxy-5'-tert. -Butylphenyl) benzotriazole 2- (2'-hydroxy-3 ', 5'-di-tert-butylphenyl) benzotriazole 2- (2'-hydroxy-3', 5'-di-tert-butylphenyl) -5-chlorobenzotriazole 2- (2'-hydroxy-3 ', 5'-di-tert-aminophenyl) benzotriazole 2- (2'-hydroxy-4'-octoxyphenyl)
Benzotriazole 2- (2'-hydroxy-3'-tert-butyl-5'-
Methylphenyl) -5-chlorobenzotriazole-salicylic acid-based phenyl salicylate p-tert-butylphenyl salicylate p-octylphenyl salicylate-benzophenone-based 2,4-dihydroxybenzophenone 2-hydroxy-4-methoxybenzophenone 2-hydroxy-4-octo Xybenzophenone 2-hydroxy-4-dodecyloxybenzophenone 2,2'-dihydroxy-4-methoxybezophenone 2,2'-dihydroxy-4,4'-dimethoxybezophenone 2-hydroxy-4-methoxy-5 Sulfobenzophenone / Cyanoacrylate-based 2-Ethylhexyl-2-cyano-3,3'-diphenylacrylate Examples include ethyl-2-cyano-3,3'-diphenylacrylate.

Further, a reactive ultraviolet absorber having a chemical structure similar to those of these ultraviolet absorbers and having a part capable of copolymerizing with the monomer for forming a contact lens base material can also be used.

Conventionally, when using an ultraviolet absorber for the purpose of absorbing ultraviolet rays, it is necessary to use a large amount of 0.5 to 10%,
As a result, a large amount of the ultraviolet absorber may suppress the polymerization reaction at the time of manufacturing the transparent lens material, which may deteriorate the physical properties of the lens material. For example, solvent resistance, heat resistance, hardness, etc. may be reduced. These physical properties also lead to a reduction in processability during lens production. Further, in an actual lens, adverse effects are likely to occur from the viewpoint of safety such as elution of additives easily. On the other hand, in the contact lens for correcting blue eyes disease of the present invention, the coloring effect of the coloring material is large, and therefore, the ultraviolet absorption The amount used can be less than the use of the agent alone. Therefore, it also has an excellent feature that the above adverse effects are reduced.

EXAMPLES Hereinafter, the present invention will be described more specifically with reference to examples.

Example 1 A mixture of 95 g of methyl methacrylate, 5 g of ethylene glycol dimethacrylate, and 0.1 g of N, N′-azobisisobutyronitrile as a polymerization initiator, and a color index Solvent Yellow (CI Sol
vent Yellow) 77 and 0.05 g of Tinuvin P (manufactured by Ciba Geigy) as an ultraviolet absorber are mixed and dissolved.
After filtering this solution through No. 2 filter paper, 15 ml of the filter solution was injected into a Pyrex test tube (internal diameter 15 mm), and then the test tube was sealed. This test tube was heated in a hot water bath at 45 ° C. for 24 hours, then heated in a hot air dryer at 60 ° C. for 5 hours and at 80 ° C. for 6 hours and cooled to room temperature. Then, the test tube was broken and the polymer was taken out. The polymer was further heated in a hot air drier at 110 ° C. for 6 hours, gradually cooled to 60 ° C. over 6 hours, and then allowed to cool to room temperature.

A disk having a thickness of 0.5 mm was prepared from the obtained polymer by cutting and polishing, and the transmittance curve was measured. This is shown in FIG.

The solid line a in FIG. 1 indicates the light transmittance curve of the polymer of Example 1 which also uses an ultraviolet absorber, and the broken line b in FIG. 1 indicates the weight which differs from the polymer of Example 2 only in that no ultraviolet absorber is used. It is the light transmittance curve of the coalescence, and it is clear that in the former case, ultraviolet absorption is completely performed, whereas in the latter case, this is not completely performed.

That is, from the results of Example 1, it is possible to reduce the amount of the coloring agent effective for absorbing light in the visible region, bring the color of the visible region closer to the crystalline lens, and further absorb the ultraviolet region of 300 to 320 nm with the ultraviolet absorber. Thus, it was revealed that it is possible to absorb the light region of 300 to 450 nm.

Next, Table 1 shows differences in hardness between the polymer of Example 1, a conventional transparent lens material using a large amount of an ultraviolet absorber and polymethylmethacrylate (PMMA).

As shown in Table 1, the material of Example 1 had a hardness equivalent to that of PMMA without addition, but the hardness of the conventional material containing a large amount of the ultraviolet absorber decreased. Therefore, the effectiveness of the contact lens of the present invention, which has no adverse effect due to the use of a large amount of the ultraviolet absorber, was shown.

Example 2 0.5 from a rod-shaped polymer obtained in the same manner as in Example 1 except that 0.02 g of CI Index Solvent Yellow 77 was used as a colorant and 0.08 g of TINUVIN P was used as an ultraviolet absorber. A mm-thick disk was prepared and the light transmittance was measured. The disc transmittance curve is shown in FIG. Curve a in FIG. 2 is the transmittance curve of the polymer disc of Example 2. Curve b is the transmittance curve of the human lens, curve c is the transmittance curve of polymethylmethacrylate (PMMA) without additives, and curves d, e, f, g, h, i, j, k FIG. 3 is a transmittance curve of a conventional polymethylmethacrylate contact lens containing an ultraviolet absorber. The transmittance curve of the disk of this example is very close to that of the human crystalline lens and this cannot be achieved with other UV absorber containing contact lens materials. Therefore, the contact lens of the present example is similar to the conventional lens material in that the light absorption in the visible region involved in blue eyesight is similar to that of the human crystalline lens, thus confirming the effectiveness of blue eye correction.

[Effects of the Invention] As is clear from the above, according to the present invention, by introducing a yellow or orange colorant and an ultraviolet absorber into a transparent lens material, a contact lens effective for correcting blue eyesight can be obtained. It was

[Brief description of drawings]

FIG. 1 and FIG. 2 are graphs showing the light transmittance curves of the polymers of Examples of the present invention and the polymers of Comparative Examples and Conventional Examples.

Claims (1)

[Claims] 1. A contact lens for correcting blue eyes disease, which comprises a transparent coloring material obtained by introducing a yellow or orange coloring agent and an ultraviolet absorber into the transparent lens material.